We are requesting funds to purchase a DakoCytomation MoFlo sorter. This instrument is needed to augment the sorting capacity of the increasingly busy University of North Carolina at Chapel Hill Flow Cytometry Facility, which is the only provider of research flow cytometry services at our large research institution. The Facility currently has 5 analytical flow cytometers (2 FACScans, 1 FACSCalibur, 2 CyAns) and one sorter. A second MoFlo sorter (the instrument described in this application), to be delivered in late March 2005, is so much needed that the University has agreed to lease (no purchase option) the instrument in order to provide the desperately needed capacity until funding can be secured to purchase the instrument. The Facility is supporting an ever-larger group of NIH-funded investigators needing increasing access to this key research technology. In CY2004 the Facility performed 7,351 hours of charged service of which 1,170 hours was for sorting. Our services support the research of over 140 laboratories (60 used sorting in CY2004) in 16 different departments and 11 research centers, at least 5 of which are designated NIH research centers. The capacity of the requested instrument will support the research of all sorter users but we have selected 21 investigators to highlight in this application as being representative of the types of research being performed. In total, all users are expected to need more than 80% of the capacity of both instruments in the upcoming year. We have chosen the MoFlo not only because we have found it to be a highly dependable, excellent instrument but also because we feel strongly that having 2 identical sorters provides strong advantages for the Facility in terms of training operators, interchange of operators between instruments, ease of troubleshooting and company communication and service. The instrument requested will provide 3 laser excitation using all diode/solid-state lasers, automated cloning, aerosol evacuation of sort chamber, digital electronics, 4-way sorting, 11 fluorescence detectors, and sample temperature control. We feel this instrument is very relevant to public health. Timely high quality basic and translational biomedical research is fundamental to the development of an understanding of disease and to the development of knowledge-based rational intervention strategies. Flow cytometry is a powerful tool in the arsenal of the biomedical researcher and, thus helps them realize their biomedical research goals. [unreadable] [unreadable]